Genetic analysis of nearly 500 cats has found similarities between feline and human cancers, potentially opening new avenues for precision treatment

Scientists have mapped the genetic landscape of cancer in domestic cats on an unprecedented scale, finding that many of the mutations driving feline tumours are also found in human cancers.

The findings, published in Science, could help researchers develop more personalised treatments for cats while providing new clues about how cancer develops and responds to drugs in humans.

The international research team analysed tumour samples from almost 500 domestic cats across five countries and created a publicly available database of genetic information from feline cancers.

Cancer is a major cause of illness and death in cats, but researchers have historically had much less information about the genetic changes behind feline tumours than they do about human and canine cancers.

“Despite domestic cats being common pets, there was very little known about the genetics of cancer in these animals until now,” said Dr Geoffrey Wood, professor of pathobiology at the University of Guelph and co-senior author of the study.

Cat and human cancers share genetic changes

Cancer can develop when mutations alter genes that control processes such as cell growth, division, DNA repair and cell death.

Researchers identified many of the same cancer-driving genes in cats that are known to play a role in human and canine cancers.

One of the strongest similarities was found in aggressive mammary cancers in cats.

More than half of the feline mammary tumours examined contained mutations in FBXW7, the most common cancer-driving gene identified in the study.

The gene normally helps regulate proteins involved in cell growth and division. When it is damaged, proteins that promote growth can accumulate and potentially allow cancer cells to survive and multiply.

Mutations in FBXW7 have also been linked to poorer outcomes in human breast cancer.

The researchers found genetic similarities between feline and human cancers affecting several other parts of the body, including the blood, bones, lungs, skin, gastrointestinal system and central nervous system.

Cats could provide clues about environmental cancer risks

Domestic cats may also offer researchers a useful way to study how genetics and the environment interact in cancer.

Because cats often share living spaces with humans, they can be exposed to some of the same environmental factors, including household chemicals, air pollution and smoke.

Studying cancers that develop naturally in pets could therefore provide clues about how environmental exposures influence cancer risk.

“This study can help us understand more about why cancer develops in cats and humans, how the world around us influences cancer risk, and possibly find new ways to prevent and treat it,” Wood said.

The findings could also have implications for cancer treatment.

Researchers found that some chemotherapy drugs were more effective against cat mammary tumour samples carrying mutated FBXW7.

However, the experiments were conducted on tissue samples, meaning the results do not yet establish that the treatment would work in living cats or humans.

The findings nevertheless point towards the potential of using genetic information to identify treatments suited to specific tumours.

This approach, known as precision oncology, uses the molecular characteristics of an individual tumour to guide treatment rather than treating every cancer of the same broad type in the same way.

“Having access to such a large set of donated tissues allowed us to assess drug responses across tumour types in a way that hasn’t been possible at this scale before,” said Dr Sven Rottenberg, co-senior author at the University of Bern.

A two-way exchange between veterinary and human medicine

The study involved researchers from the Wellcome Sanger Institute, the University of Guelph’s Ontario Veterinary College, the University of Bern and other institutions.

Rather than collecting new samples specifically for the project, researchers analysed DNA from tissue samples that veterinarians had already collected during routine diagnostic procedures.

This allowed them to study naturally occurring cancers across a large number of cats and compare genetic changes between different types of tumours.

The researchers say the work supports the broader One Medicine approach, which recognises the links between human and veterinary medicine.

Treatments developed for human cancer could potentially be studied in animals with naturally occurring tumours, while discoveries from veterinary cancer research could provide insights for human medicine.

Dogs have already benefited from comparatively extensive research into cancer genetics, and the researchers hope the new feline database will help close the gap for cats.

“When knowledge and data flows between different disciplines, we can all benefit,” said Bailey Francis, co-first author at the Wellcome Sanger Institute.

The researchers now hope the genetic resource will help advance personalised cancer care for cats.

Dr Louise Van Der Weyden, senior author at the Wellcome Sanger Institute, said the study provides a foundation for further research into precision treatment for feline cancer, with potential lessons for human medicine.